1. Field of the Invention
The present invention relates to a network opening method in a manufacturing system using robots.
2. Description of the Related Art
In a manufacturing system using robots, particularly, industrial robots (referred to, e.g., as a Flexible Manufacturing System (FMS)), information technology (IT) has been progressed in such a manner that a plurality of robot controllers (or control units) individually connected to a plurality of robots are also connected to various automation apparatuses, such as a programmable controller (PC), a computer, a switch, a sensor, a motor, a hydraulic or pneumatic device, a parts feeder, etc., through a network, so as to carry out a signal and/or data communication, and thus to automatically perform manufacturing, inspection, storage, management, etc., of products.
As a network used in the above-described manufacturing system, there are known (1) an upper network (referred to as an “information network” in the present application) for mainly communicating production control data, design data, logistics data, etc., between computers, and (2) an intermediate or lower network (referred to as a “control network” in the present application) for communicating operation state data, operation instructions, etc., between PCs or between a PC and a robot controller. The lower network also functions as a wire-saving network for connecting respective robot controllers with various input-output units, such as actuators, sensors, etc., and communicating ON/OFF signals, etc. Recently, a manufacturing system, in which a plurality of robot controllers are connected through the information network to a computer in a direct way, so as to facilitate a central management of a plurality of robots, has also appeared.
As a representative example of the information network, there is known the Ethernet (registered trademark) based on IEEE802.3. Also, as the control network, there are known the DeviceNet (registered trademark), the Profibus (registered trademark), the Interbus (registered trademark), the OPCN-1 (registered trademark), etc., each of which seing an open network.
In the manufacturing system using robots, there is a case where a control network must be constructed, in addition to the construction of the information network, for a plurality of robot controllers. When constructing the two systems of networks, conventionally, conditions (such as addresses) required for opening the two networks are respectively set in every one of the robot controllers. According to this conventional network-constructing method, time is spent for opening the two network systems and, as a result, there is worry about a delay in starting a manufacturing system when, e.g., the configuration of the system is changed.